Mysql 构造函数必须在JSP、JDBC、servlet和表单中被称为超级错误

我正在为我的web应用程序创建注册表单，当我尝试访问并注册新用户时，出现以下错误：

java.lang.VerifyError: (class: eBooks/Data/UserDB, method: <init> signature: ()V) Constructor must call super() or this() java.lang.VerifyError: (class: eBooks/Data/UserDB, method: <init> signature: ()V) Constructor must call super() or this()
at eBooks.controller.RegisterUserServlet.doPost(RegisterUserServlet.java:62)

这是RegisterUserServlet：

package eBooks.controller;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.http.Cookie;

import eBooks.business.User;
import eBooks.business.Account;
import eBooks.Data.UserDB;


public class RegisterUserServlet extends HttpServlet
{

    public void doPost(HttpServletRequest request,
                       HttpServletResponse response)
                       throws IOException, ServletException
    {
        HttpSession session = request.getSession();

        String fName = request.getParameter("fName");
        String lName = request.getParameter("lName");
        String emailAddress = request.getParameter("emailAddress");
        String password = request.getParameter("password");
        String dateOfBirth = request.getParameter("dateOfBirth");
        String phone = request.getParameter("phohe");
        String address = request.getParameter("address");
        String city = request.getParameter("city");
        String country = request.getParameter("country");
        String state = request.getParameter("country");
        String accountType = request.getParameter("accountType");
        //TO DO: Account acctTypeList = request.getParameter("acctTypeList");  add this an object first

        User user = new User();

        user.setfName(fName);
        user.setlName(lName);
        user.setEmailAddress(emailAddress);
        user.setPassword(password);
        user.setDateOfBirth(dateOfBirth);
        user.setAddress(address);
        user.setCity(city);
        user.setCountry(country);
        user.setState(state);
        user.setZipcode(phone);

        //TODO: user.setAccountType(accTypeList); -- Ask Jassin


        // Add information to the database

        if(UserDB.emailExists(emailAddress))
            UserDB.update(user);
        else
            UserDB.update(user);

        session.setAttribute("User", user);

        Cookie emailCookie = new Cookie("emailCookie", emailAddress);
        emailCookie.setMaxAge(60*60*24*365*2);
        emailCookie.setPath("/");
        response.addCookie(emailCookie);

        String url = "WEB-INF/view/registration_confirmation.jsp";
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(url);
        dispatcher.forward(request, response);


    }


}

我是网络开发新手，我只需要朝着正确的方向努力来解决这个问题

---

我正在使用glassfish和mysql。

刚刚解决了这个问题–将所有文件移动到一个新项目中，并手动创建了web.xml，现在运行良好。感谢@ErnestFriedman Hill

此错误实际上表明您正在使用的编译器中存在错误！您使用什么将*.java文件转换为*.class文件？@ErnestFriedman Hill感谢您的回复。我使用的是Netbeans 7.1，没有框架，只是解决了这个问题——将所有文件移到了一个新项目中，并手动创建了web.xml，现在运行良好。谢谢@ErnestFriedman HillSo也许您的类文件已损坏。很高兴你能跑起来。

package eBooks.controller;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import javax.servlet.http.Cookie;

import eBooks.business.User;
import eBooks.business.Account;
import eBooks.Data.UserDB;


public class RegisterUserServlet extends HttpServlet
{

    public void doPost(HttpServletRequest request,
                       HttpServletResponse response)
                       throws IOException, ServletException
    {
        HttpSession session = request.getSession();

        String fName = request.getParameter("fName");
        String lName = request.getParameter("lName");
        String emailAddress = request.getParameter("emailAddress");
        String password = request.getParameter("password");
        String dateOfBirth = request.getParameter("dateOfBirth");
        String phone = request.getParameter("phohe");
        String address = request.getParameter("address");
        String city = request.getParameter("city");
        String country = request.getParameter("country");
        String state = request.getParameter("country");
        String accountType = request.getParameter("accountType");
        //TO DO: Account acctTypeList = request.getParameter("acctTypeList");  add this an object first

        User user = new User();

        user.setfName(fName);
        user.setlName(lName);
        user.setEmailAddress(emailAddress);
        user.setPassword(password);
        user.setDateOfBirth(dateOfBirth);
        user.setAddress(address);
        user.setCity(city);
        user.setCountry(country);
        user.setState(state);
        user.setZipcode(phone);

        //TODO: user.setAccountType(accTypeList); -- Ask Jassin


        // Add information to the database

        if(UserDB.emailExists(emailAddress))
            UserDB.update(user);
        else
            UserDB.update(user);

        session.setAttribute("User", user);

        Cookie emailCookie = new Cookie("emailCookie", emailAddress);
        emailCookie.setMaxAge(60*60*24*365*2);
        emailCookie.setPath("/");
        response.addCookie(emailCookie);

        String url = "WEB-INF/view/registration_confirmation.jsp";
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(url);
        dispatcher.forward(request, response);


    }


}